Abstract:
The US has developed a pocket-size drone dubbed the Nano Hummingbird for the way it flaps its tiny robotic wings as a mini-spy plane capable of manoeuvring on the battlefield and in urban areas.

The battery-powered drone, which looks like a bird for potential use in spy missions, was built for the Pentagon's research arm as part of a series of experiments in nanotechnology. It is the result of a five-year effort, announced on Thursday by the Pentagon and AeroVironment of California.